Damping devices of this kind are, for example, part of clutch installations such as hydrodynamic converters. A converter of this kind has, for example a rotating housing that is capable of transmitting driving torque to the damping device by means of a friction locking clutch, sometimes called a “lockup clutch.” The converter also has a turbine wheel mounted rotatably inside the housing.
A combustion engine exhibits irregularities due to the succession of combustion events in the engine cylinders. Torsion damping means allow these irregularities to be filtered before driving torque is transmitted to a transmission. This is because the vibrations must be damped before they enter the transmission and produce unacceptably troublesome noise.
To accomplish this, it is known to interpose a torsion damping device between the engine shaft and the transmission shaft. The torsion damping device is generally arranged in a clutch system that allows temporary rotational connection of the engine shaft to the transmission shaft.
The torsion damping device generally has circumferentially acting elastic members that are interposed between a torque input element and a torque output element.
In so-called “long travel” damping devices, the elastic members are mounted, in groups of at least two elastic members, in series between the input element and output element.
In such a configuration, a phasing tab is interposed between the two elastic members of said group. This ensures that the elastic members work substantially in circumferential compression. The phasing tabs are, for example, carried by phase washers.
The input washers are generally arranged at the axial ends of the device in order to sandwich the output washers and the phase washer. A conventional design of this kind is evident because the output washers are coupled to the transmission shaft by means of a central hub, while the engine shaft is coupled to input washers via their periphery.
The torsion damper device also has two output webs that are arranged axially on either side of each input washer.